Lung Cancer Glossary

Adenocarcinoma - This form of non-small cell lung cancer begins in the glandular cells that line the lungs. Thirty-five percent of U.S. lung cancer patients have adenocarcinoma.

Learn the definitions of terms frequently used when describing lung cancer.

Asbestos - A fine, silica dust that, when inhaled, has the potential to cause asbestosis and mesothelioma. Asbestos is present in some building and insulation materials.

Alveoli - Small air sacs in the lungs that expel carbon dioxide from the bloodstream and accept oxygen in to it.

Benign Tumor - A non-cancerous growth, visible as a mass of cells. Benign tumors do not invade other cells or spread to other parts of the body; however, they should be monitored regularly or removed.

Bronchi - Tubes that branch from the trachea, into the separate lobes of the lungs. Within the right and left lobes of the lungs the bronchi branch further into bronchial tubes.

Bronchoscopy - A procedure used to test for lung disease in which a small camera is attached to a tube that is moved down the trachea. Samples of lung secretions or lung tissue may be taken during the bronchoscopy procedure.

Carcinogen - A cancer-causing agent. Asbestos, radon, benzene, arsenic, and uranium are examples of carcinogens known to cause lung cancer.

Chemotherapy - A lung cancer treatment that damages cancerous cells, causing them to stop dividing. Chemotherapy also affects normally dividing cells in the body, such as those in the skin, digestive tract and blood. For this reason, a patient may become quite sick as a result of chemotherapy treatment.

Immunotherapy - A cancer treatment that is still under development, immunotherapy causes a body's immune system to react against foreign, cancerous cells.

In Situ Cancer - Cancer that is in situ or "in its original position" has not spread to other areas of the body. In situ cancer is less aggressive than invasive cancer.

Large Cell Lung Cancer- Undifferentiated large cell carcinoma produces tumors along the bronchi and is identified by the large, round shape of the cancer cells.

Lobectomy - The lungs are divided into separate sections or "lobes." The left lung has two lobes and the right lung has three lobes. During a lobectomy a surgeon will remove an entire lobe of a patient's lung.

Lung Cancer- The leading cause of cancer death in the U.S., lung cancer is broken down into two groups: small cell lung cancer and non-small cell lung cancer. Although there is no cure, preventative measures can drastically reduce a person's risk of developing lung cancer.

Malignant Tumor - A growth of abnormal cells that is cancerous. Malignant tumors invade other cells and spread to other parts of the body.

Mesothelioma- A rare form of lung cancer caused by exposure to asbestos. Mesothelioma affects the pleura of the lungs, often over a period of many years.

Metastasis - The spread of cancer from one part of the body to another, or a new (secondary) cancer growth.

Non-Small Cell Lung Cancer- A lung cancer in the form of squamous cell carcinoma, adenocarcinoma, or large cell carcinoma. Non-small cell lung cancers affect between 70 and 80 percent of lung cancer patients.

Oncologist - A doctor who has specialized in the study of cancer. A lung cancer patient's oncologist will diagnose his or her cancer, determine how much it has spread, and perform (or advise on) appropriate treatment.

Photodynamic Therapy (PDT) - A laser therapy treatment for cancer patients. A chemical that stays within cancerous cells is administered to the patient. The chemical, when activated by a laser, kills or weakens the cells.

Pneumonectomy - The removal of an entire lung from the body of a cancer patient. Performed if the procedure may halt the spread of cancer.

Pulmonary Pleura - A serous (or "serum containing") membrane that encloses the lungs. The pulmonary pleura contains two tissue layers that are separated by serous fluid.

Radiation Therapy - A treatment used to target cancer in specific areas of the body. Radiation therapy can be performed internally or externally and is usually used in combination with chemotherapy or surgery.

Radioimmunotherapy - A treatment that combines the effectiveness of radiation treatment with immunotherapy. The body is given radiolabeled antibodies. These antibodies attach to cancerous cells (thereby alerting the immune system) and weaken them with attached radiation.

Radon - A radioactive gas that is created when uranium breaks down. Radon carries no scent, taste, or color and thus may accumulate within homes and buildings unchecked. Radon is a leading cause of lung cancer, second only to smoking in the U.S.

Secondhand Smoke - Also referred to as "sidestream smoke" or "environmental tobacco smoke," secondhand smoke poses a significant risk to those who are exposed to it. The Environmental Protection Agency estimates that 3,000 lung cancer deaths are caused by "passive smoking" yearly. Infants and children are especially susceptible to secondhand smoke.

Small Cell Lung Cancer - Between twenty and twenty-five percent of lung cancer cases are caused by small cell carcinomas. Small call lung cancer is more likely to spread to other parts of the body than non-small cell lung cancer.

Smoking Cessation - A person who quits smoking will greatly reduce his or her chance of developing lung cancer, but the process is difficult as tobacco contains nicotine, a highly addictive alkaloid. Many nicotine replacement therapies are available to help smokers, as are "quit" programs and support groups.

Sputum Cytology - The study of cells within a person's sputum or phlegm. Sputum cytology can reveal the presence of cancerous cells in the lungs.

Squamous Cell Carcinoma - The most common form of lung cancer, squamous cell carcinoma originates in the bronchi and is slow to spread to other parts of the body.

Staging - Lung cancer is staged according to the extent to which it has spread. Non-small cell lung cancer stages are separated into Stage 0, IA, IB, IIA, IIB, IIIA, IIIB, and IV. Small cell lung cancer is normally staged as either limited or extensive.

Systemic Treatment - Treatment to destroy or weaken cancer cells that may have spread to other parts of the body.

Trachea - The windpipe or tube that brings air from the larynx to the bronchial tubes.

Tumor - Cells that reproduce abnormally may form masses called tumors. A benign tumor remains in one position and is not cancerous. A malignant tumor is cancerous and will spread to or invade other cells.